The invention set forth in this specification pertains to a new and improved tub box structure.
More specifically the present invention relates to a tub box which is considered to be an improvement over a prior tub box or tub box structure as set forth in the U.S. Pat. No. 3,593,344 issued July 20, 1971 entitled "Tub Box Structure." A tub box structure as set forth in this prior patent utilizes two tub shaped containers assembled together in a face to face relationship. The lower of these two containers is constructed so as to include an opening adapted to receive a pipe and perforate ears adapted to be utilized in supporting the complete tub box structure. As the tub box structure is used stakes such as lengths of concrete reinforcing rod are secured to the ears so as to hold the tub box structure in a desired location until such time as the area immediately adjacent to the lower or bottom container is filled in and until a slab is poured relative to the complete tub box structure.
Normally the ground will be filled in around the tub box prior to the slab being poured to such an extent that the slab will only extend around a portion of the upper container. It is normally intended to utilize this prior tub box structure as shown in the prior patent so that after the slab is poured and has set up a portion of the uppermost container can be exposed so that it will be severed from the remainder of the structure in order to provide access into the interior of the tub box structure so that plumbing can be connected in a normal manner.
Although tub box structures as indicated in the preceding are undoubtedly desirable and utilitarian it is considered that several aspects of them are somewhat undesirable and/or disadvantageous. Because of the manner in which these prior tub box structures are constructed there is always at least a degree of danger that the two tub like containers may be displaced from one another to a limited extent as such a prior tub box structure is being installed. As a consequence of this there is always a danger that the interior of the tub box or tub box structure will become contaminated with ambient materials and/or concrete. Further, it is not always reasonably possible to locate a pipe entering a structure through a peripheral or side wall as illustrated in the prior U.S. patent. In addition it frequently is somewhat disadvantageous to have to find a tool to sever a part of the top or upper container in such a prior tub box structure after a concrete slab has been poured around the complete tub box structure and has been allowed to set up.